How to define multiple keys for @CachePut?

Question

How can I use @CachePut on an object, and update a cache by multiple properties of it?

Example: Cached persons are added to PERSONS cache every time the 'findOneByFirstnameAndLastname()` method is invoked.

If the Person object is persisted, I also want the cache to update the person. But how can I tell @CachePut to use both firstname+lastname as the key for the PERSONS cache? Right now the save() method does not update the cache...

public interface PersonRepository extends CrudRepository<Person, Long> {
    //assume there is only one valid person
    @Cachable("PERSONS")
    Person findOneByFirstnameAndLastname(String firstname, String lastname);

    //TODO how to update cache by entity.firstname + entity.lastname
    @CachePut("PERSONS")
    @Override
    Person save(Person entity);
}

Answer 1

At the end I succeeded in using reference to the parameters (#p1, #2) during lookip and reference to #result.* during persist:

@Cacheable(cacheNames = "PERSONS", key = "#p1 + #p2")
Person findByFirstnameAndLastName(String firstname, String lastname);

@CachePut(cacheNames = "PERSONS", key = "#result.firstName + #result.lastName")
Person save(Person person);

Yet I don't know why I could not use #firstname + #lastname or #person.firstname + #person.lastname, but Spring constantly complains about having null parameters then. Maybe Spring cannot resolve the parameter names at this stage, whysoever.